Modular Access to Fluorinated Quaternary Stereocenters via Palladium/Lewis Base Synergistic Catalysis

Area of Science:

• Organic Chemistry
• Catalysis
• Fluorine Chemistry

Background:

• Stereocontrolled construction of fluorinated quaternary stereocenters in acyclic systems is a major synthetic hurdle.
• Existing methods often require directing groups or struggle with fluoronucleophile activation and stereochemical control.

Purpose of the Study:

• To develop a novel synergistic catalytic platform for the direct coupling of alpha-fluoro-alpha-aryl acetates with allenes or 1,3-dienes.
• To overcome limitations in activating fluoronucleophiles and achieving stereochemical control in acyclic fluorinated compound synthesis.

Main Methods:

• Utilized a synergistic palladium/Lewis base catalytic system.
• Employed axial-chiral Lewis bases in cooperation with palladium catalysts.
• Coupled alpha-fluoro-alpha-aryl acetates with allenes or 1,3-dienes without the need for directing groups.

Main Results:

• Successfully achieved stereocontrolled construction of fluorinated quaternary stereocenters in acyclic systems.
• Demonstrated control over both enantioselectivity and diastereoselectivity through the use of axial-chiral Lewis bases.
• Showcased broad substrate scope, including aromatic, heterocyclic, and aliphatic systems.
• Confirmed scalability and synthetic versatility via downstream transformations.

Conclusions:

• The developed method provides efficient access to diverse acyclic fluorinated architectures.
• This work addresses critical gaps in fluorinated stereochemical synthesis.
• The synergistic catalytic approach enhances the practical utility of such systems in organic synthesis.